This research is to investigate the relationship between DNA polymerase and malignancy. Our emphasis has been to analyze the different DNA polymerases in normal and leukemic lymphocytes to determine their physical properties and their mechanism of catalysis. The broad objectives of the proposal are: 1. To characterize and extensively purify DNA polymerases from phytohemagglutinin-stimulated lymphocytes of patients with chronic lymphatic leukemia. 2. To understand the mechanism by which E. coli DNA polymerase I copies natural RNA templates and to utilize this mechanism to synthesize large amounts of DNA complementary to unique RNA templates. 3. To determine if all DNA polymerases including "reverse transcriptases" are zinc metalloenzymes and to determine the requirement for zinc during the transformation of human lymphocytes.